Have you noticed small, white, pimple-like bumps on the back of your arms? You might also have spotted these skin marks on your face, buttocks, or thighs. If you have, you may have a skin condition called keratosis pilaris.

Keratosis pilaris is common, especially among people who already have dry skin or eczema. The cause is an accumulation of keratin, a protective protein in your skin. Keratin may build up because of underlying conditions, but it also occurs in otherwise healthy people. When it accumulates, keratin blocks hair follicles and forms the scaly, acne-like bumps, which measure about 1 mm to 2 mm.

Sandpapery and resembling goose bumps, the marks are harmless and painless, though occasionally itchy. The bumps can appear red or pink when inflamed, and often in clusters or patches. They tend to clear up during summer months or pregnancy and flare up in the dry air of winter. Many cases of keratosis pilaris resolve over time.

While there is no cure for keratosis pilaris, you can improve the appearance of your skin:

Since dry skin can worsen the condition, keep yourself - and your skin - well hydrated. Drink plenty of water and use a humidifier in your home on drier days.

Take short, warm water showers, since hot water can strip natural protective oils from your skin.

Use gentle soaps or cleansers, avoiding potentially irritating ingredients like detergent or fragrance.

After showering or bathing, lightly pat-dry your skin before applying a cream to seal in the moisture.

Choose a moisturizer containing alpha-hydroxy acids or urea.

Hydrocortisone cream (0.5% to 1%) can also relieve itchiness.

To prevent scarring, infection, or redness, do not scrub or pick at the bumps.

Keratosis pilaris can be a difficult condition to get satisfactory treatment results. If you are concerned about the appearance of your skin, contact a doctor or dermatologist, who may prescribe a stronger medicated cream or ointment.